The present invention relates generally to hydraulically driven agricultural rakes and, more particularly, to a hydraulic system for controlling the hydraulically operated components on a unitized raking implement.
Unitized raking implements in which two rake baskets are permanently and movably supported on the frame of the mechanism to permit a positioning of the rake baskets in a number of orientations, yet provide a transport position in which the rake baskets are carried at a minimal width orientation, have been developed to provide a multiple number of functions that can be accomplished with the rake baskets. Examples of such unitized rakes can be found in U.S. Pat. No. 4,343,142 and in the commercial embodiments manufactured by Vermeer Manufacturing Company as Model R-23 Twinrake and by the Allen Manufacturing Company as its Model 852 rake.
These unitized raking implements typically include hydraulically driven motors for rotating the rake baskets and can also include hydraulic cylinders for positioning the rake baskets laterally of the center line of the raking implement, swinging the rake baskets relative to the frame to vary the orientation of the rake baskets relative to the direction of travel of the implement, and generally vertically lifting the rake baskets relative to the ground. Often, the tractors used to tow unitized raking implements are provided with only one hydraulic circuit to which the implement's hydraulic system can be connected. Selected operation of the implement's hydraulic components is desirable to provide maximum operator convenience and efficiency of operation of the implement.
One solution to the problem of selectively controlling the implement hydraulic components from a single prime mover hydraulic system circuit can be seen in the aforementioned U.S. Pat. No. 4,343,142. This solution utilizes a plurality of, individually controlling fluid to each hydraulic component, valves with a cable control to each valve. Such a solution requires a plurality of cables and control levers mounted in a control box, resulting in potential confusion to the operator and an individual control of each component. It would be desirable to provide a hydraulic system for a unitized rake in which the number of control levers would be minimized and in which operation of some of the related hydraulic components would be simultaneously or automatically actuated.